Quasi-radial heatsink with rectangular form factor and uniform fin length

ABSTRACT

In some embodiments, a heatsink includes a thermally conductive core and at least ten thermally conductive fins extending quasi-radially from the thermally conductive core, wherein most of the fins are of uniform length, and wherein at least a portion of the thermally conductive core is shaped such that the fins having uniform length form a substantially rectangular cross sectional form factor. Other embodiments are disclosed and claimed.

The invention relates to thermal management devices. More particularly,some embodiments of the invention relate to a quasi-radial heatsink witha rectangular form factor and uniform fin length.

BACKGROUND AND RELATED ART

Many electronic devices require or benefit from the use of thermalmanagement devices, such as heatsinks.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of the invention will be apparent from the followingdescription of preferred embodiments as illustrated in the accompanyingdrawings, in which like reference numerals generally refer to the sameparts throughout the drawings. The drawings are not necessarily toscale, the emphasis instead being placed upon illustrating theprinciples of the invention.

FIG. 1 is a schematic view of a heatsink, in accordance with someembodiments of the invention.

FIG. 2 is another schematic view of the heatsink from FIG. 1, inaccordance with some embodiments of the invention.

FIG. 3 is a schematic view of an electronic system, in accordance withsome embodiments of the invention.

FIG. 4 is another schematic view of the electronic system from FIG. 3,in accordance with some embodiments of the invention.

FIG. 5 is a front view of another heatsink in accordance with someembodiments of the invention.

FIG. 6 is a bottom view of the heatsink from FIG. 5, in accordance withsome embodiments of the invention.

FIG. 7 is a bottom, perspective view of the heatsink from FIG. 5, inaccordance with some embodiments of the invention.

FIG. 8 is a front view of another heatsink, in accordance with someembodiments of the invention.

FIG. 9 is a bottom view of the heatsink from FIG. 9, in accordance withsome embodiments of the invention.

FIG. 10 is a bottom, perspective view of the heatsink from FIG. 8, inaccordance with some embodiments of the invention.

FIG. 11 is a front view of another heatsink, in accordance with someembodiments of the invention.

FIG. 12 is a bottom, perspective view of the heatsink from FIG. 11, inaccordance with some embodiments of the invention.

FIG. 13 is an enlarged, fragmented view of some fins from the heatsinkfrom FIG. 11, in accordance with some embodiments of the invention.

FIG. 14 is a side view of the heatsink from FIG. 11, in accordance withsome embodiments of the invention.

FIG. 15 is a front view of another heatsink, in accordance with someembodiments of the invention.

FIG. 16 is a top, perspective view of the heatsink from FIG. 15, inaccordance with some embodiments of the invention.

FIG. 17 is a bottom view of the heatsink from FIG. 15, in accordancewith some embodiments of the invention.

FIG. 18 is a top view of the heatsink from FIG. 15, in accordance withsome embodiments of the invention.

FIG. 19 is a bottom, perspective view of the heatsink from FIG. 15, inaccordance with some embodiments of the invention.

FIG. 20 is a flow diagram, in accordance with some embodiments of theinvention.

FIG. 21 is an exploded, perspective view of another electronic system,in accordance with some embodiments of the invention.

FIG. 22 is a perspective view of the assembled electronic system fromFIG. 21, in accordance with some embodiments of the invention.

DESCRIPTION

In the following description, for purposes of explanation and notlimitation, specific details are set forth such as particularstructures, architectures, interfaces, techniques, etc. in order toprovide a thorough understanding of the various aspects of theinvention. However, it will be apparent to those skilled in the arthaving the benefit of the present disclosure that the various aspects ofthe invention may be practiced in other examples that depart from thesespecific details. In certain instances, descriptions of well knowndevices, circuits, and methods are omitted so as not to obscure thedescription of the present invention with unnecessary detail.

With reference to FIGS. 1-2, a heatsink 10, in accordance with someembodiments of the invention, includes a thermally conductive core 12and at least ten thermally conductive fins 14 extending quasi-radiallyfrom the thermally conductive core 12. In the example shown in FIGS.1-2, the heatsink 10 includes seventeen fins 14 extending from the core12. In accordance with some embodiments of the invention, most of thefins 14 may be of uniform length and at least a portion of the thermallyconductive core 12 is shaped such that the fins 14 having uniform lengthform a substantially rectangular form factor.

For example, the dashed rectangular box 16 in FIG. 2 illustrates how thefins 14 form a substantially rectangular form factor. For example, aportion of the core 12 inside in the box 16 may be formed with a complexshape which positions the tips of the uniform length fins 14 along theperimeter of the box 16. The shape of the core 12 may bulge or recess inaccordance with the angles of the fins 14 and their respective positionsaround the core 12. Advantageously, some embodiments of the inventionmay provide thermal gain by reducing conduction spreading resistancethrough the core 12 by having core material concentrated in a centralportion of the heatsink 10.

As used herein, uniform may mean the same, substantially the same, orwithin reasonable variation (e.g. due to manufacturing precision,tolerances, etc.). As used herein, quasi-radial may mean preciselyradial, substantially radial, or just having a general radialarrangement (e.g. a plurality of fins distributed around a core withvarying angular orientations, even if the angles of the fins do notchange regularly or the fins do not intersect a common point).

For example, in some embodiments, the fins having uniform length mayalso have uniform thickness profiles. The fins having uniform length andthickness profiles may also have uniform tip-to-tip spacing. In someembodiments, the fins having uniform length and thickness profiles mayalso have uniform cross-sectional area between the fins. The heatsink 10may be made by any of a number of well known, conventional manufacturingtechniques including, for example, machining, casting, molding, orextrusion. In some applications, it may be preferred that all of thefins are configured to be suitable for manufacturing by an extrusionprocess. For example, the thermally conductive core and the fins may bemade from aluminum.

In some applications, the thermally conductive core may include a copperportion (e.g. a copper slug). For example, some embodiments may furtherinclude two fins on opposite sides of the thermally conductive core 12which are longer than the other fins 14 and are adapted to be utilizedas structural members to transfer a preload to a heat source. The twolonger fins may also be thicker than the other fins 14. In someapplications, all but a small subset of the fins may be of uniformlength (e.g. generally six or fewer fins may be different lengths inorder to accommodate the structural fins).

With reference to FIGS. 3-4, an electronic system 30 includes a systemboard 32, an electronic component 34 on the system board, and a heatsink36 thermally coupled to the electronic component 34. For example, theheatsink includes a thermally conductive core 42 and at least tenthermally conductive fins 44 extending quasi-radially from the thermallyconductive core 42, wherein most of the fins 44 are of uniform lengthand wherein at least a portion of the thermally conductive core 42 isshaped such that the fins 44 having uniform length form a substantiallyrectangular form factor.

For example, the electronic component 34 may be a processor. Forexample, the system 30 may further include a double data rate memorymodule 36 coupled to the system board 32. For example, the system 30 mayfurther include a rectangular form factor duct 38 positioned around theheatsink 40 and a fan 46 positioned to provide cooling air through theduct 38.

The heatsink 40 may include fins 44 having uniform length, uniformthickness profiles, and/or uniform tip-to-tip spacing or uniformcross-sectional area between the fins. The core 42 and fins 44 may bemade from aluminum and may be configured to be suitable formanufacturing by an extrusion process. In some applications, the core 42may include a copper slug. For example, the heatsink 40 may include twolonger, thicker fins on opposite sides of the core 42 which are adaptedto be utilized as structural members to transfer a preload to theelectronic component 34.

An aluminum extrusion heat sink, having the complex shape in accordancewith some embodiments of the present invention, may be particularlyuseful for space constrained systems consistent with small form factors.For example, some embodiments of the invention may find utility in aBalanced Technology Extended (BTX) desktop computer form factor. Forexample, some embodiments of the invention may provide a quasi-radialfin heat sink compliant with the form factor specifications for spaceconstrained systems shaped to fit within a rectangular duct. The finsmay be of uniform length, increasing or maximizing their surface areawhile maintaining a constant or substantially constant height/thicknessratio. Advantageously, the complex shape of the core, in accordance withsome embodiments of the invention, may provide a large surface area todistribute the fins, allowing greater spacing between fins and/or ahigher fin count. For low cost applications, the greater spacing betweenthe fins may allow the complex shaped heat sink, in accordance with someembodiments of the invention, to be manufactured using an extrusionprocess.

With reference to FIGS. 5-7, a heatsink 50, in accordance with someembodiments of the invention, includes a thermally conductive core 52and at least ten thermally conductive fins 54 extending quasi-radiallyfrom the thermally conductive core 52. In the example shown in FIGS.5-7, the heatsink 50 includes thirty-one fins 54 extending from the core52. In general, utilizing more fins provides larger surface area and mayimprove the performance of the heatsink for some applications. Inaccordance with some embodiments of the invention, most of the fins 54may be of uniform length and at least a portion of the thermallyconductive core 52 is shaped such that the fins 54 having uniform lengthform a substantially rectangular form factor.

For example, in some embodiments, the fins 54 having uniform length mayalso have uniform thickness profiles. The fins 54 having uniform lengthand thickness profiles may also have uniform tip-to-tip spacing. In someembodiments, the fins 54 having uniform length and thickness profilesmay also have uniform cross-sectional area between the fins. In someapplications, it may be preferred that all of the fins 54 are configuredto be suitable for manufacturing by an extrusion process. For example,the thermally conductive core 52 and the fins 54 may be made fromaluminum. The core 52 may include a pedestal or base portion 53, whichmay be integral with the core 52 (e.g. monolithic from an extrusion ormolding process). Advantageously, the core 52 may provide a concentratedcore area which may provide lower conduction resistance to heatconduction (e.g. compared to flat-plate based heat sinks).

As shown in FIG. 5, all but six of the fins 54 may be of uniform length(e.g. a small subset of fins may be different lengths in order toaccommodate the structural fins). For example, some embodiments mayfurther include two fins 56 and 58 on opposite sides of the thermallyconductive core 52 which are longer than the other fins 54 and areadapted to be utilized as structural members to transfer a preload to aheat source. The two longer fins 56 and 58 may also be thicker than theother fins 54. Advantageously, the complex shape of the core 52 mayallow a higher or maximum fin count while reducing or minimizing theconduction resistance in the core itself. In some applications, the core52 may be contained within the shadow of the fan hub, presentingrelatively more open area to the airflow field.

With reference to FIGS. 8-10, a heatsink 80, in accordance with someembodiments of the invention, includes a thermally conductive core 82and at least ten thermally conductive fins 84 extending quasi-radiallyfrom the thermally conductive core 82. In the example shown in FIGS.5-7, the heatsink 80 includes thirty-one fins 84 extending from the core82. In accordance with some embodiments of the invention, most of thefins 84 may be of uniform length and at least a portion of the thermallyconductive core 82 is shaped such that the fins 84 having uniform lengthform a substantially rectangular form factor.

For example, in some embodiments, the fins 84 having uniform length mayalso have uniform thickness profiles. The fins 84 having uniform lengthand thickness profiles may also have uniform tip-to-tip spacing. In someembodiments, the fins 84 having uniform length and thickness profilesmay also have uniform cross-sectional area between the fins. In someapplications, it may be preferred that all of the fins 84 are configuredto be suitable for manufacturing by an extrusion process. For example,the thermally conductive core 82 and the fins 84 may be made fromaluminum.

For example, as shown in FIGS. 8-10, the thermally conductive core 82includes a copper portion 83. For example, the copper portion 83 may bea right cylindrical copper slug. Some extrusion processes may be able toincorporate the copper portion 83. Alternatively, the core 82 and fins84 may be extruded and thereafter drilled, milled, or machined toprovide an opening in the core 82 for the copper portion 83. In someapplications, the copper portion 83 may be secured in the opening byshrink fitting. Other conventional manufacturing techniques may beutilized to provide the core 82 with the copper portion 83. For someapplications, copper may provide better thermal performance as comparedto aluminum, although generally at a higher cost.

As shown in FIG. 8, all but six of the fins 84 may be of uniform length.For example, some embodiments may further include two fins 86 and 88 onopposite sides of the thermally conductive core 82 which are longer thanthe other fins 84 and are adapted to be utilized as structural membersto transfer a preload to a heat source. The two longer fins 86 and 88may also be thicker than the other fins 84.

With reference to FIGS. 11-14, a heatsink 110, in accordance with someembodiments of the invention, includes a thermally conductive core 112and at least ten thermally conductive fins 114 extending quasi-radiallyfrom the thermally conductive core 112. In the example shown in FIGS.11-14, the heatsink 110 includes thirty-one fins 114 extending from thecore 112. In accordance with some embodiments of the invention, most ofthe fins 114 may be of uniform length and at least a portion of thethermally conductive core 112 is shaped such that the fins 114 havinguniform length form a substantially rectangular form factor.

With reference to FIG. 13, most of the fins 114 have uniform length(e.g. the length L is the same or about the same for those fins). Inthis example, the fins 114 having uniform length may also have uniformthickness profiles (e.g. those fins have about the same thicknessprofile T). Those skilled in the art will appreciate that the thicknessT is not necessarily constant along the length of the fins and the fins114 may have a slight taper. For example, the fins may be about 0.1 mmthinner at the tip than they are at the point they attach to the core112. However, the thickness profile may be considered uniform among finshaving substantially the same taper. In this example, the fins 114having uniform length and thickness profiles may also have uniformtip-to-tip spacing (e.g. about the same distance S between tips of thefins).

In some examples, a uniform cross-sectional area gap A may be providedbetween the fins. For example, the spacing between fins at the attachpoint to the conductive core may be held constant, and the tip-to-tipspacing may be varied slightly until a uniform cross-sectional area isachieved. This configuration may results in a slight variation intip-to-tip spacing (e.g. within about a 1 mm range, visually thetip-to-tip may still appear uniform). In some applications, the uniformcross-sectional area my have a slight performance advantage over theuniform tip-to-tip spacing.

In some applications, it may be preferred that all of the fins 114 areconfigured to be suitable for manufacturing by an extrusion process. Forexample, the thermally conductive core 112 and the fins 114 may be madefrom aluminum.

As shown in FIG. 11, all but four of the fins 114 may be of uniformlength (e.g. a small subset of fins may be different lengths in order toaccommodate the structural fins). For example, some embodiments mayfurther include two fins 116 and 118 on opposite sides of the thermallyconductive core 112 which are longer than the other fins 114 and areadapted to be utilized as structural members to transfer a preload to aheat source. The two longer fins 116 and 118 may also be thicker thanthe other fins 114.

With reference to FIGS. 15-19, a heatsink 150, in accordance with someembodiments of the invention, includes a thermally conductive core 152and at least ten thermally conductive fins 154 extending quasi-radiallyfrom the thermally conductive core 152. In the example shown in FIGS.15-19, the heatsink 150 includes thirty-one fins 154 extending from thecore 152. In accordance with some embodiments of the invention, most ofthe fins 154 may be of uniform length and at least a portion of thethermally conductive core 152 is shaped such that the fins 154 havinguniform length form a substantially rectangular form factor.

With reference to FIG. 15, most of the fins 114 have uniform length. Inthis example, the fins 154 having uniform length may also have uniformthickness profiles. In this example, the fins 154 having uniform lengthand thickness profiles may also have uniform tip-to-tip spacing oruniform cross-sectional area between the fins. In some applications, itmay be preferred that all of the fins 154 are configured to be suitablefor manufacturing by an extrusion process. For example, the thermallyconductive core 152 and the fins 154 may be made from aluminum.

As shown in FIG. 15, all but four of the fins 154 may be of uniformlength. For example, some embodiments may further include two fins 156and 158 on opposite sides of the thermally conductive core 152 which arelonger than the other fins 154 and are adapted to be utilized asstructural members to transfer a preload to a heat source. The twolonger fins 156 and 158 may also be thicker than the other fins 154.Advantageously, some embodiments of the heatsink 150 may be used toprovide low-cost thermally efficient heatsink in space constrainedsystems (e.g. as described in connection with FIGS. 21-22 below).

Advantageously, embodiments of the invention may provide one or more ofthe following design benefits. The complex core shape may create alarger surface area to attach the fins (e.g. as compared to a flat,circular, or elliptical shaped core), thus allowing more fins spacedfurther apart. The compact, concentrated core shape may provide lowerconduction resistance to heat conduction (e.g. compared to flat-platebased heat sinks). The complex core shape together with uniform finlength may provide a rectangular profile heat sink, which may fullyutilize the cooling solution volume available in some small form factorspecifications.

Some embodiments of the invention may be configured to be compliant withextrusion manufacturability constraints, thus enabling a low costmanufacturing solution. In some applications, embodiments of theheatsink can be made entirely from aluminum, thus reducing or minimizingmaterial cost and shipping weight In some applications, the core of theheatsink may be positioned almost entirely in the region of the systemfan hub, thus reducing or minimizing airflow impedance. In someembodiments, two fins may be able to be used as structural members totransfer the required preload, sometimes with a slight thicknessincrease.

With reference to FIG. 20, some embodiments of the invention involveforming a thermally conductive core (e.g. at block 200), and forming atleast ten thermally conductive fins extending quasi-radially from thethermally conductive core, wherein most of the fins are of uniformlength, and wherein at least a portion of the thermally conductive coreis shaped such that the fins having uniform length form a substantiallyrectangular form factor (e.g. at block 201).

For example, the fins having uniform length may also have uniformthickness profiles (e.g. at block 202). For example, the fins havinguniform length and thickness profiles may also have uniform tip-to-tipspacing (e.g. at block 203) or uniform cross-sectional area between thefins (e.g. at block 204). Some embodiments may further involve formingall of the fins to be suitable for manufacturing by an extrusion process(e.g. at block 205). Some embodiments may further involve extruding thethermally conductive core and fins from aluminum (e.g. at block 206).

Some embodiments of the invention may involve forming the thermallyconductive core to include a copper portion (e.g. at block 207). In someapplications, all but six or fewer of the fins may be the same length(e.g. a small subset of the fins may be different lengths to accommodatestructural fins). Some embodiments may further involve forming two finson opposite sides of the thermally conductive core which are longer thanthe other fins and are adapted to be utilized as structural members totransfer a preload to a heat source (e.g. at block 208). For example,the two longer fins may also be thicker than the other fins (e.g. atblock 209).

With reference to FIGS. 21-22, an electronic system 210 includes asystem board 212, an electronic component 214 on the system board, and aheatsink 216 thermally coupled to the electronic component 214. Forexample, the heatsink 216 includes a thermally conductive core 222 andat least ten thermally conductive fins 224 extending quasi-radially fromthe thermally conductive core 222, wherein most of the fins 224 are ofuniform length and wherein at least a portion of the thermallyconductive core 222 is shaped such that the fins 224 having uniformlength form a substantially rectangular form factor.

For example, the electronic component 214 may be a processor. Forexample, the system 210 may further include a double data rate memory, achipset, a memory controller hub, an i/o controller, and/or otherelectronic components coupled to the system board 212. For example, thesystem 210 may further include a rectangular form factor duct 218positioned around the heatsink 216 and a fan 220 positioned to providecooling air through the duct 218.

The heatsink 216 may include fins 224 having uniform length, uniformthickness profiles, and/or uniform tip-to-tip spacing or uniformcross-sectional area between the fins. The core 222 and fins 224 may bemade from aluminum and may be configured to be suitable formanufacturing by an extrusion process. In some applications, the core222 may include a copper slug. For example, the heatsink 216 may includetwo longer, thicker fins 226 on opposite sides of the core 222 which areadapted to be utilized as structural members to transfer a preload tothe electronic component 214. For example, the fins 226 may be receivedwithin recessed portions 228 of the duct 218 which may be utilized toapply downward pressure on the heatsink 216 when the duct 218 is securedto the system board 212.

The foregoing and other aspects of the invention are achievedindividually and in combination. The invention should not be construedas requiring two or more of such aspects unless expressly required by aparticular claim. Moreover, while the invention has been described inconnection with what is presently considered to be the preferredexamples, it is to be understood that the invention is not limited tothe disclosed examples, but on the contrary, is intended to covervarious modifications and equivalent arrangements included within thespirit and the scope of the invention.

1. An apparatus, comprising: a thermally conductive core; and at leastten thermally conductive fins extending quasi-radially from thethermally conductive core, wherein most of the fins are of uniformlength, and wherein at least a portion of the thermally conductive coreis shaped such that the fins having uniform length form a substantiallyrectangular form factor.
 2. The apparatus of claim 1, wherein the finshaving uniform length also have uniform thickness profiles.
 3. Theapparatus of claim 2, wherein the fins having uniform length andthickness profiles also have uniform tip-to-tip spacing.
 4. Theapparatus of claim 2, wherein the fins having uniform length andthickness profiles also have uniform cross-sectional area between thefins.
 5. The apparatus of claim 4, wherein the all of the fins areconfigured to be suitable for manufacturing by an extrusion process. 6.The apparatus of claim 5, wherein the thermally conductive core and thefins are aluminum.
 7. The apparatus of claim 1, wherein the thermallyconductive core includes a copper portion.
 8. The apparatus of claim 1,further comprising: two fins on opposite sides of the thermallyconductive core which are longer than the other fins and are adapted tobe utilized as structural members to transfer a preload to a heatsource.
 9. The apparatus of claim 8, wherein the two longer fins arealso thicker than the other fins.
 10. A method, comprising: forming athermally conductive core; and forming at least ten thermally conductivefins extending quasi-radially from the thermally conductive core,wherein most of the fins are of uniform length, and wherein at least aportion of the thermally conductive core is shaped such that the finshaving uniform length form a substantially rectangular form factor. 11.The method of claim 10, wherein the fins having uniform length also haveuniform thickness profiles.
 12. The method of claim 11, wherein the finshaving uniform length and thickness profiles also have uniformtip-to-tip spacing.
 13. The method of claim 11, wherein the fins havinguniform length and thickness profiles also have uniform cross-sectionalarea between the fins.
 14. The method of claim 13, further comprising:forming all of the fins to be suitable for manufacturing by an extrusionprocess.
 15. The method of claim 14, further comprising: extruding thethermally conductive core and fins from aluminum.
 16. The method ofclaim 10, further comprising: forming the thermally conductive core toinclude a copper portion.
 17. The method of claim 10, furthercomprising: forming two fins on opposite sides of the thermallyconductive core which are longer than the other fins and are adapted tobe utilized as structural members to transfer a preload to a heatsource.
 18. The method of claim 17, wherein the two longer fins are alsothicker than the other fins.
 19. A system, comprising: a system board;an electronic component on the system board; and a heatsink thermallycoupled to the electronic component, the heatsink comprising: athermally conductive core; and at least ten thermally conductive finsextending quasi-radially from the thermally conductive core, whereinmost of the fins are of uniform length, and wherein at least a portionof the thermally conductive core is shaped such that the fins havinguniform length form a substantially rectangular form factor.
 20. Thesystem of claim 19, wherein the fins having uniform length also haveuniform thickness profiles.
 21. The system of claim 20, wherein the finshaving uniform length and thickness profiles also have uniformtip-to-tip spacing.
 22. The system of claim 20, wherein the fins havinguniform length and thickness profiles also have uniform cross-sectionalarea between the fins.
 23. The system of claim 22, wherein all of thefins are configured to be suitable for manufacturing by an extrusionprocess.
 24. The system of claim 23, wherein the thermally conductivecore and the fins are aluminum.
 25. The system of claim 19, wherein thethermally conductive core includes a copper portion.
 26. The system ofclaim 19, further comprising: two fins on opposite sides of thethermally conductive core which are longer than the other fins and areadapted to be utilized as structural members to transfer a preload tothe electronic component.
 27. The system of claim 26, wherein the twolonger fins are also thicker than the other fins.
 28. The system ofclaim 19, wherein the electronic component comprises a processor. 29.The system of claim 28, further comprising: a double data rate memorycoupled to the system board.
 30. The system of claim 19, furthercomprising: a rectangular form factor duct positioned around theheatsink; and a fan positioned to provide cooling air through the duct.